Satellites in orbit provide directed beams using antennas aimed precisely towards a target region on the Earth to provide high signal quality for transmitting and/or receiving ground stations in that region. However, due to a variety of factors, the directed beams may drift away from the intended region, significantly reducing the transmitted/received signal quality and potentially interrupting service (i.e. a communications link) between the satellite and transmitting/receiving ground stations. The drift of the directed beams is a particular problem for multi-spot beam satellites because of the narrow beamwidth of each directed beam. Maintaining an accurate orientation of the satellite antenna or antennas during orbit is necessary to ensure that the directed beams service the intended target region without degradations and interruptions. To compensate for any variations in satellite antenna orientation that are affecting the transmitted/received beams, satellites and satellite components, for example, antennas, require minor pointing corrections.
Some current solutions for determining pointing corrections include utilizing “on-board” auto-tracking systems or multi-station tracking. However each existing solution has drawbacks. Accordingly, improved techniques for ground-based determination and correction of pointing error of a satellite are disclosed herein.